I successfully used it on my five day adventure along the Knobstone Trail in southern Indiana, and even though it's web-based it hardly consumed any battery life on my old first-gen Pixel XL.

It's set up currently to support a single trail, where the trail and trail markers are deployed with the rest of the app. So it's single-use in that way. For future trips, I can simply swap out the GPX files and deploy.

I am releasing it with an open source license in case anyone wants to use it as a boilerplate to create their own.